lsmaxxed

I have read the ls1how to writeup as well as watched the video. I have swapped 4 springs out so far by having my air compressor running into my sparkplug hole with a compression test kit at 60-100 psi. but on the last spring i was compressing the valve dropped about halfway down. so i grabbed the crankshaft pulley and quickly turned it over.. i was able to pull it all the way up but there has got to be a full proof way to make sure the valve wont drop into the cylinder. any advice is appreciated!!

CattleAc

iTrader: (7)

I've always used the compressed air method myself with good results...but, I have a large 2-stage comp that can keep a constant 160 lbs...

lsmaxxed

are you saying that you use a compressor to the spark plug hole at 160 psi to hold the valves up?

conan

iTrader: (5)

I've used the TDC method 3 time now with no problems.

CattleAc

iTrader: (7)

I usually regulate it to 120 PSI...but, yes...

Old Geezer

iTrader: (3)

Parachute cord fed into the cyl. Then ease the crank over to push the piston/rope up to hold the valves in place....

Atomic

iTrader: (37)

I just make sure I dont clank the engine while doing the swap...there is a small amount of friction on the seal that can hold the valve. Putting the piston at TDC is also a good method. The piston will stop the valve from falling all the way down.

srs bzns

iTrader: (3)

Second the parachute cord idea. Seen it done after the pressurizing the cylinder method was a little shakey

roastin240

iTrader: (13)

Find TDC in each cylinder and do it. Quickest way is put a straw in the spark plug hole and rotate the crankshaft until you see the straw go up and down and stop about where the straw is at its highest point (TDC). This will keep the valve from falling too far into the cylinder....you wont lose a valve this way.

svede1212

iTrader: (3)

Exactly

Zmg00camaross

iTrader: (11)

TDC method for me!

speedtigger

iTrader: (16)

X2. I have never done it any other way with the heads installed.

But, if for any reason you need to let the air out of the cylinder or walk away, I put rubber bands on the valve stem in the interim.

68Poncho

iTrader: (1)

Make sure the intake and exhaust valve you are swapping the springs on are closed. Pull the valve core from your compression tester, disconnect the gauge, screw it in the spark plug hole and connect the house air to it. It will keep the valves up while you swap the springs. If you hear lots of rushing air then one of the valves are still open.

saccitycorvette

iTrader: (3)

This is how I do it too!

99Bluz28

iTrader: (35)

Bingo!

Exactly how I do it!

soundengineer

iTrader: (16)

after you air up a cylinder...and begin to compress the spring... tap them with a hammer to free them up

the only way they will open the valve is if they stick to the retainers and top of the valve
tapping them firmly with a hammer (enough to get a nice popping noise from the air rushing out of the valve) will keep them from ever having an issue with compressed air.

speedtigger

iTrader: (16)

This is good advise but be sure to use either a nylon hammer or a block of wood between the hammer and the spring compressor. What you don't want to happen is for a steel hammer to contact the valve tip.

soundengineer

iTrader: (16)

I'm talking a light tap.....like let gravity do the work...it doesnt take much, but it has to have some mass to overcome the spring pressure and air pressure in the first place (a nylon hammer often does not have enough mass to do any good)
if you hit it hard enough to damage a valve...then you were hitting WAY too hard in the first place...

a small ball peen will do the trick...

if you are really worried about it...coat the hammer with some Plastidip first

35th SS

iTrader: (2)

same here.just did my vette this past Sept.

Atomic

iTrader: (37)

I usually tap mine with the socket wrench im using to compress the tool...